1. Field of the Invention
The present invention relates to a lighting device and a display apparatus using the same.
2. Description of Related Art
Self-luminous elements such as a LED (Light Emitting Diode) and an organic EL (Electro Luminescence) are currently at an advanced stage of development, so that they have the same level of energy efficiency as a fluorescent lamp. The use for such self-luminous elements as lightings to replace existing lightings such as an incandescent lamp and a fluorescent lamp according to their characteristics has been contemplated. Because most lightings are used as a white light source, it is necessary to produce white light when using a self-luminous element as well.
However, a self-luminous element normally can emit light in a very narrow wavelength range only. One approach to obtain white light from such a self-luminous element is to mix light with different wavelengths or colors. This technique has the advantage of excellent color reproducibility through adjustment of the light intensity of each wavelength but also has the disadvantage of difficulty in mixing light in a small space to cause an increase in the size of a lighting device.
Japanese Unexamined Patent Application Publication No. 2000-4050 discloses an illuminant that is capable of emitting light in many directions by covering the surface of a LED with a number of beads.
As described above, the technique of mixing light with different wavelengths for the purpose of obtaining a desired color of light using a self-luminous element has the problem that it is difficult to mix light in a small space, which causes a larger lighting device.